Efficient synthesis of mono- and disubstituted 2,3-dihydroquinazolin-4(1H)-ones using aluminum methanesulfonate as a reusable catalyst

A wide range of mono- and disubstituted 2,3-dihydroquinazolin-4(1H)-ones were synthesized via a one-pot three components condensation of isatoic anhydride, aldehydes, and ammonium salts or primary amines in the presence of aluminum methanesulfonate in EtOH/H2O solution. The catalyst is reusable and could be recycled for several runs without any distinct decrease in its efficiency. A plausible mechanism for this one-pot three components reaction was proposed.